Ideal for your longest runs in cool spring conditions, the Mountain Hardwear Kor Preshell Pullover Jacket delivers weather-resistant protection and high levels of breathability for hard-to-guess weather. Described by Mountain Hardwear as a "Preshell", this ultralight pullover strikes a balance between a performance top and a weatherproof shell. It accomplishes this task thanks to its Pertex Quantum Air fabric, which is both air-permeable and weather-resistant, protecting you from light rain and wind without trapping your body heat as you pick up the pace. The Kor Preshell is also light in weight and made with an engineered stretch fabric ensuring light and easy movement on blistering trail runs. Best of all, when calm and mild weather returns, you can stuff the entire jacket into its chest pocket, toss it in a pack or pocket, and continue on your way.